I want to replay some pokemon games, but most of them are too easy and pretty boring for extra playthroughs. Nuzlocke can make it a little better, but still not great.

Are there any romhacks that keep the game mostly the same, but improve the levels and pokemon of trainers?

In particular, I was hoping to start with one of the Kanto games. Preferably the remakes but originals would also be good.